/**
 * initPerfectScrollbar
 * @param {Object} $scrollBlock DOM scrollable element.
 * @returns {void}
 */
function initPerfectScrollbar($scrollBlock, options) {

    'use strict';

    if (!$scrollBlock || !$scrollBlock.length) {
        return false;
    }

    for (let i = 0; i < $scrollBlock.length; i++) {

        if ($scrollBlock[i].classList.contains('ps')) {
            Ps.update($scrollBlock[i]);
        }
        else {
            if (!options) {
                options = {};
            }

            Ps.initialize($scrollBlock[i], {
                'handlers': ['click-rail', 'drag-thumb', 'wheel', 'touch'],
                'minScrollbarLength': 20,
                ...options
            });
        }
    }
}

/**
 * initTextareaScrolling
 * @param {Object} $textarea DOM textarea element.
 * @returns {void}
 */
function initTextareaScrolling($textarea) {

    'use strict';

    const $scrollBlock = $textarea.closest('.textarea-scroll') || $textarea.parent();
    let $preview = $('.textarea-clone', $scrollBlock);

    if ($preview.length === 0) {
        $preview = $('<div class="textarea-clone"></div>');
        $scrollBlock.append($preview);
    }

    const updateScroll = () => {

        $preview.safeHTML(`${$textarea.val().replace(/\n/g, '<br />')} <br>`);
        $textarea.height($preview.height());
        initPerfectScrollbar($scrollBlock);
    };

    updateScroll();

    $textarea.rebind('input.updateScroll change.updateScroll', () => {
        updateScroll();
    });

    // Avoid multi handling
    if (!$scrollBlock.hasClass('dragScroll')) {
        $scrollBlock.addClass('dragScroll');

        const [block] = $scrollBlock;
        const [textarea] = $textarea;

        const onMouseMove = (ev) => {
            const offsets = block.getBoundingClientRect();

            if (ev.clientY < offsets.top + 15) {
                block.scrollTop = Math.max(block.scrollTop - 3, 0);
            }
            else if (ev.clientY > offsets.top + block.offsetHeight - 15) {
                block.scrollTop = Math.min(block.scrollTop + 3, block.scrollHeight - block.offsetHeight);
            }
        };
        const onMouseUp = () => {
            document.removeEventListener('mouseup', onMouseUp);
            document.removeEventListener('mousemove', onMouseMove);
        };

        textarea.addEventListener('mousedown', () => {
            document.addEventListener('mouseup', onMouseUp);
            document.addEventListener('mousemove', onMouseMove);
        });
    }
}


/**
 * Scroll to an element if it's not visible in DOM
 * @param {Object} $scrollBlock DOM scrollable element.
 * @param {Object} $scrollTo DOM target element.
 * @returns {void}
 */
function scrollToElement($scrollBlock, $scrollTo) {

    'use strict';

    if ($scrollTo.length && $scrollBlock.length) {

        const scrollToOffset = $scrollTo.offset().top;
        const scrollToHeight = $scrollTo.hasClass('expanded')
            ? $scrollTo.parent().outerHeight() : $scrollTo.outerHeight();
        const scrollBlockOffset = $scrollBlock.offset().top;
        const scrollBlockHeight = $scrollBlock.height();
        const scrollValue = $scrollBlock.scrollTop();

        if (scrollToOffset - scrollBlockOffset + scrollToHeight > scrollBlockHeight) {

            $scrollBlock.scrollTop(
                scrollToOffset - scrollBlockOffset
                    + scrollToHeight - scrollBlockHeight + scrollValue + 8
            );
        }
        else if (scrollToOffset < scrollBlockOffset) {

            $scrollBlock.scrollTop(
                scrollToOffset - scrollBlockOffset + scrollValue - 8
            );
        }
    }
}

function reselect(n) {
    'use strict';

    if (d) {
        console.debug('reselect(%s)', n, [window.selectionManager]);
    }
    if (window.selectionManager) {
        return selectionManager.reinitialize();
    }
    $('.ui-selected').removeClass('ui-selected');

    if (!Array.isArray($.selected)) {
        $.selected = [];
    }

    var ids = $.selected.map((h) => {
        if (h && typeof h === 'object') {
            h = h.h;
        }
        return String(h).replace(/[^\w-]/g, '');
    });

    // Just scroll to file in mobile weblClient
    if (is_mobile && n && $.selected.length) {
        mobile.cloud.scrollToFile($.selected[0]);
        return;
    }

    if (window.selectionManager) {
        selectionManager.clear_selection();
    }

    for (var i = ids.length; i--;) {
        if (window.selectionManager) {
            selectionManager.add_to_selection(ids[i], n, i);
        }
        $('#' + ids[i]).addClass('ui-selected');

        if (n) {
            $('#' + ids[i] + ' .grid-status-icon').addClass('new');
            $('#' + ids[i] + ' .file-status-icon').addClass('new');
        }
    }

    if (n) {
        let $el;
        let $scrollBlock;

        if (M.onIconView) {
            $scrollBlock = $('.file-block-scrolling.ps:not(.hidden, .megaList)');
            $el = $('a.ui-selected');
        }
        else {
            $scrollBlock = $('.grid-scrolling-table.ps:not(.hidden, .megaList)');
            $el = $('tr.ui-selected');
        }

        if ($el.length && $scrollBlock.length) {
            $scrollBlock.scrollTop($el.position().top + $scrollBlock.scrollTop());
        }
    }
}

Object.defineProperty(self, 'Ps', {value: freeze({
    initialize(node, opts) {

        'use strict';

        if (!node) {
            return;
        }

        if (node.Ps) {
            node.Ps.destroy();
        }

        node.Ps = new PerfectScrollbar(node, opts);
    },
    update(node) {

        'use strict';

        if (node && node.Ps) {

            const _getXnY = () => node.classList.contains('ps--active-x') && node.classList.contains('ps--active-y');
            const prevXnY = _getXnY();

            node.Ps.update();

            if (_getXnY() !== prevXnY) {
                node.Ps.update();
            }
        }
    },
    destroy(node) {

        'use strict';

        if (node && node.Ps) {
            node.Ps.destroy();
        }
    },
    enable(node) {

        'use strict';

        if (node) {
            node.classList.remove('ps-disabled');
        }
    },
    disable(node) {

        'use strict';

        if (node) {
            node.classList.add('ps-disabled');
        }
    },
})});
